The revelation drew a fiery exchange between Indigenous Greens senator Lidia Thorpe and assistant minister Amanda Stoker, who was appearing before Senate estimates on behalf of the home affairs minister.

Responding to the revelation, Senator Stoker listed further statistics about deaths in custody so Australians could "understand the state of play".

"In the public's mind, deaths in prison custody conjures a particular image and it is helpful to have an understanding of the different ways (this occurs)," she said.

The rate of Indigenous deaths in custody has been lower than non-Indigenous people since 2003/04, Senator Stoker said.

Sixteen out of 113 deaths in custody in 2019/20 were Indigenous and almost nine in 10 Indigenous deaths in custody were attributed to natural causes, she said.

The statistics prompted Senator Thorpe to fire back, calling Indigenous deaths in custody a national crisis.

"We need to stop police from killing Aboriginal people in this country," she said.

There are also additional systemic issues in Australia that resulted in a high rates of underlying issues for Indigenous people, she said.

The Australian Institute of Criminology will move to report deaths in custody on a quarterly basis.

The next report will be made available on the agency's website in April next year and will cover January to March.

Australian Associated Press